For example, European Patent No. 0404359A1 discloses that 5,11-dihydrodibenzo[b,e][1,4]thiazepine derivatives are useful as a calcium channel blocker having a selectivity for the gastrointestinal tract. Quinn, P. et al., Brit. J. Pharmacol. 1994, 112(Suppl.), Abst p573 and Wallis, R. M. et al., Brit. J. Pharmacol. 1994, 112(Suppl.), Abst p574 disclose that (S)-5-[1-[2-(Methoxyphenyl)ethyl]pyrrolidin-2-ylmethyl]-5,11-dihydrodibenz o[b,e][1,4]thiazepine maleate which is one of the above-mentioned derivatives has the same activity as mentioned abov e. However, the above-mentioned compounds are problematic in that they exhibit an anticholinergic activity which gives a side effect such as hydrodipsia, mydriasis or the like.
In recent years, as the social environment has become complicated, a lot of people have come to be under great stress, and there have been a large number of patients suffering from an irritable bowel syndrome of which main symptoms are abnormal bowel movement, abdominal pain and the like. To cope with such diseases, an anticholinergic agent, a laxative agent, an antidiarrheal drug, a drug for controlling intestinal function, a mucosa paralyzant, a drug for controlling an intestinal tract moving function, an agent of controlling an autonomic nerve, a herb medicine, an antianxiety agent, an antidepressant, a hypnotic agent, a neuroleptic agent and the like have been used so far. However, clinical effects of these agents are insufficient, and these agents are not necessarily satisfactory in view of the side effects. Accordingly, the development of a new type of a drug which is free of a side effect and which has an excellent activity of improving a digestive tract moving function has been in demand.